In process automation technology, field devices are often used which serve for registering and/or influencing process variables. Examples of such field devices are fill level meters, mass flow measuring devices, pressure and temperature measuring devices, etc., which as sensors register the corresponding process variables, fill level, flow, pressure, and temperature.
Serving for the influencing of process variables are the so called actuators, e.g., valves which change the flow of a liquid in a section of pipeline, or pumps which change the fill level in a container.
A large number of such field devices are manufactured and sold by the firm Endress+Hauser.
As a rule, field devices in modern fabrication plants are connected via a fieldbus (Profibus®, Foundation® Fieldbus, etc.) with control systems or units. These serve for process control, process visualization, process monitoring, as well as for configuring and parametering of the field devices. Field devices execute various functions within the process control. For special standard functions, e.g., PID-controller, so-called function blocks with defined communication interfaces are available. These function blocks represent, on the basis of corresponding algorithms which are executed in the microprocessors of the individual field devices, special application functions. Field devices with microprocessors are also referred to as intelligent field devices or smart field devices.
An essential aspect of the function blocks is that they have defined interfaces and, therefore, can be easily interconnected for complex control strategies.
In the Foundation® Fieldbus specifications, which are publicly available, various standard function blocks are specified. Typical function blocks for field devices are “Analog Input” AI, “Analog Output” AO, “Discrete Input” DI, “Discrete Output” DO, “PID-control” PID. Besides these basic function blocks, there are also special function blocks “Analog Alarm,” “Arithmetic,” “Device Control.” Recently, also flexible function blocks of the Foundation® Fieldbus are specified, which are freely programmable according to the IEC Standard 61131 (e.g., Supervisory Data Acquisition). In the IEC Standard 61158 are specified, besides different fieldbus systems, also the Foundation® Fieldbus technology.
Before a field device can be introduced in a process environment, it must be configured and parametered. For this, among other things, the loading of the control strategy into the corresponding field devices is necessary. A known application which makes this possible is the system SYSCON (of the firm SMAR). With this application, also the concrete interconnection of the individual function blocks, as well as the chronological course of the control strategy can be tested.
For changing the parameters of a function block, first this function block must be called up within a corresponding operating program. Thereupon, the parameters of this function block displayed in the operating program can be changed by the user. If a plurality of parameters of a control loop, e.g., a cascade control, must be changed, then the corresponding individual function blocks must be sequentially found within the operating program, called up, and the necessary parameter changes effected. This is very complicated and time consuming for the user. The user must also, in order to get certain information of a plurality of function blocks, in each case, call-up the corresponding function blocks separately, in a complicated manner, to have them then be displayed on the user interface of the operating program.